Spinning of viscose



3,041,132 EallNNlNG F VHSCOSE Edward M. Simon, Jr., Metuchen, N.J.,assignnr to Atlas Chemical Industries Inc., Wilmington, Del., acorporation of Delaware No Drawing. Original application Jan. 31, 1955,Ser. No. 485,347, new Patent No. 2,941,892, dated June 21, 1960. Dividedand this application Jan. 28, 1960, Ser. No. 5,113

8 (Ila.

This invention relates to the regeneration of cellulose from viscosesolutions and more particularly to the manufacture of regeneratedcellulose articles such as yarn and film from viscose, and is a divisionof my copending application, Serial No. 485,347, and now US. Patent No.2,941,892.

It is an object of the invention to provide a process for producingregenerated cellulose yarn having novel and desirable properties.

Another object of the invention is to provide a process for producinghigh-tenacity regenerated cellulose yarn.

A further object is to provide a process whereby unripened viscose canbe spun to produce a high-tenacity, fatigue-resistant regeneratedcellulose fiber having improved soil and abrasion resistance.

A still further object is to provide novel viscose compositions adaptedto the spinning of high-tenacity regenerated cellulose yarns. v

The above and other projects will become more apparent in the course ofthe following description of the invention and in the appended claims.

The above objects are accomplished in accordance with the invention byincorporating in the viscose solution to be spun a compound which is apolyhydric alcohol, containing from 3 to 6 carbon atoms and at least /2.as many hydroxyl groups as carbon atoms, a hydroxyethyl orpolyhydroxyethyl ether of such an alcohol, or a polyoxyethylene ether ofsuch an alcohol. The said compound may be represented by the genericformula wherein R is the hydrocarbon residue of a polyhydric alcoholcontaining from 3 to 6 carbon atoms and at least as many hydroxyl groupsas carbon atoms, In and 11 each has any value from 0 to 6 such thattheir sum is equal to the number of hydroxyl radicals in said polyhydricalcohol, and x has any value from 0 to 20. An exemplary list ofcompounds so-defined includes glycerol, propylene glycol,pentaerythritol, erythritol, xylitol, the several desoxy hexitols,sorbitol, mannitol, hydroxyethyl glycerol, hexahydroxyethyl sorbitol,penta hydroxyethyl mannitol, the polyoxyethylene ether of glycerolcontaining 50 oxyethylene groups, the polyoxyethylene ether of sorbitolcontaining 100 oxyethylene groups, the polyoxy ethylene ether ofpentaerythritol containing 60 oxyethylene groups, the polyoxyethyleneether of mannitol containing 120 oxyethylene groups, and the like.

The defined compounds are soluble in viscose solutions and may beincorporated therein at any stage of the viscose process after thecellulose is dissolved. For effective results, from about 0.75 to about4% by weight of the polyhydric alcohol or ether-alcohol based on theweight of cellulose in the solution is employed. The composition of theviscose may vary widely as is known in the art. It may be formed fromcotton linters or from wood pulp as the source of cellulose, and maycontain from 4% to of cellulose in a solution containing from 4% to 8%of alkali metal hydroxide. The amount of carbon disulfide used inxanthation may be from 25% to 50%.

3,04Ll32 Patented June 26, 1962 The viscose solutions of the invention,i.e., those containing the modifying polyhydroxy compounds hereinbeforedefined, may be employed in the normal manner for the production ofregenerated cellulose films, and yarns. Suitable spinning orregenerating baths contain sulfuric acid, zinc sulfafe andsodiumsulfate. Preferred spinning baths contain from 4% to 12% sulfuricacid, from 1% to 10% zinc sulfate and from 13% to 25% sodium sulfate.

The following non-limiting examples illustrate the preparation ofviscose solutions and production of regenerated cellulose yarntherefrom, both in accordance with the invention.

Example I A cotton linters viscose containing 7% cellulose and 6.6%sodium hydroxide is prepared in the conventional manner except thatduring the dissolution of the Xanthated cellulose in the aqueous sodiumhydroxide, 1% by weight, based on the cellulose content, of thepolyoxyethylene ether of sorbitol containing oxyethylene groups per molis added and thoroughly dispersed therein. The resulting viscosesolution is spun in an unripened state into a bath containing 7%sulfuric acid, 8% zinc sulfate and 17% sodium sulfate. The spinning iscarried out on conventional spinning equipment to produce a regeneratedcellulose yarn of high tensile strength which is resistant to abrasion.

Example 11 Viscose containing 7% cellulose, 6% sodium hydroxide and0.055% sorbitol is prepared as follows: Alkali cellulose aged to obtaina suitable viscose viscosity is xanthated with 36% carbon disulfide. Thexanthate crumbs are dissolved in aqueous solution containing sodiumhydroxide solution and sorbitol in amounts to furnish the indicatedpercentages. After mixing, the viscose is filtered, deaerated andfinally spun in an unripened state. The coagulating and regeneratingbath contains 8% sulfuric acid, 8% zinc sulfate and 23% sodium sulfate.Yarns with smooth surface and high tenacity are obtained.

Example III A wood pulp viscose containing 7% cellulose and 6.6% sodiumhydroxide is prepared in the conventional manner except that 3%, basedon the weight of cellulose, of the polyoxyethylene ether of mannitolcontaining 20 oxyethylene groups per mol is incorporated therein duringdissolution of the xanthate in the alkali solution. After filtration anddeaeration of the prepared viscose the solution is ripened for 36 hoursand spun into a regenerating bath containing 8% sulfuric acid, 8% zincsulfate and 23% sodium sulfate. The resulting yarn is fatigue resistantand of low soil retention.

In the illustrative examples, sorbitol and polyoxyethylene hexitols havebeen employed as the viscose modifying agents. Similar improved resultsmay be obtained by employing any of the polyhydric alcohols and/ ortheir oxyethylene or polyovxyethylene ethers as defined hereinbefore.

What is claimed is:

1. A method of producing regenerated cellulosic structures whichcomprises spinning a viscose solution containing from 0.75% to 4.0%,based on the weight of the cellulose, of a polyoxyethylene ether of ahexitol, into an acid regenerating bath containing sulfuric acid, zincsulfate and sodium sulfate.

2. A method of producing regenerated cellulosic structures whichcomprises spinning into an acid regenerating bath containing sulfuricacid, zinc sulfate and sodium sulfate a viscose solution containing from0.75% to 4.0% based on the weight of the cellulose, of a polyoxyethyleneether of sorbitolcontaining from 1 to 100 oxyethylene groups per mol ofsorbitol.

3. A method of producing regenerated cellulosic structures whichcomprises spinning a viscose solution containing from 4.0% to 10.0%cellulose, from 4.0% to 8.0% alkali metal hydroxide and from 0.75% to4.0%, based on the cellulose, of a polyoxyethylene ether of a hexitolcontaining up to 20 oxyethylene groups in each polyoxyethylene chaininto an aqueous sulfuric acid spinning bath containing 4.0% to 12.0%sulfuric acid, 1.0% to 10.0% Zinc sulfate and 13.0% to 25.0% sodiumsulfate.

4. A method of producing regenerated cellulosic structures as in claim 3wherein said hexitol is sorbitol.

5. A method of producing regenerated cellulosic structures whichcomprises spinning into an acid regenerating bath containing sulfuricacid, zinc sulfate and sodium sulfate a viscose containing in solution apolyoxyethylene ether of a 3 to 6 carbon polyhydric alcohol containingup to 20 oxyethylene groups per hydroxyl radical of said alcohol, thesaid polyhydric alcohol containing at least /a as many hydroxyl groupsas carbon atoms.

6. A method of producing regenerated cellulosic structures as in claim 5wherein said polyhydric alcohol is sorbitol.

7. A method of producing regenerated cellulosic yarns from viscose whichcomprises spinning 'into an acid regenerating bath containing sulfuricacid, zinc sulfate and sodium sulfate a viscose containing in solutionfrom 0.75 to 4.0%, based on the cellulose content, of a polyoxyethyleneether of a 3 to 6 carbon polyhydric alcohol containing up to 20oxyethylene groups per hydroxyl radical of said alcohol, the saidpolyhydric alcohol containing at least /3 as many hydroxyl groups ascarbon atoms.

8. A method of producing regenerated cellulosic yarns as in claim 7wherein said polyhydric alcohol is sorbitol.

Elod et al.: Reyon Zellwolle und Andere Chemiefasern, Jahrg. 1955, No.33, pages 322-323.

5. A METHOD OF PRODUCING REGENERATED CELLULOSIC STRUCTURES WHICHCOMPRISES SPINNING INTO AN ACID REGENERATING BATH CONTAINING SULFURICACID, ZINC SULFATE AND SODIUM SULFATE A VISCOSE CONTAINING IN SOLUTION APOLYOXYETHYLENE ETHER OF A 3 TO 6 CARBON POLYHYDRIC ALCOHOL CONTAININGUP TO 20 OXYETHYLENE GROUPS PER HYDROXYL RADICAL OF SAID ALCOHOL, THESAID POLYHYDRIC ALCOHOL CONTAINING AT LEAST 2/3 AS MANY HYDROXYL GROUPSAS CARBON ATOMS.